SCIENTIFIC SUMMARY. 
219* 
ZOOLOGY AND COMPARATIVE ANATOMY. 
The Skeleton of the Ostrich Group. — At a recent meeting of the Zo- 
ological Society of London, Professor Mivart, F.R.S., read a paper on the 
axial skeleton of the Struthionidee, and pointed out that, judging by the 
characters of the axial skeleton, the Emeu presents the least differential 
type ; from which Rhea diverges most on the one hand and Apteryx on the 
other ; that the resemblance between Drcmceus and Casuarius is exceedingly 
close, while the axial skeleton of Dinornis is intermediate between that of 
Casuarius and Apteryx ; its affinities, however, with the existing New 
Zealand form very decidedly predominating. 
The Measurement of Blood Corpuscles of Animals. — A communication was 
read before the Zoological Society of London, from Mr. George Gulliver,. 
E.R.S., F.Z.S., containing measurements of the red corpuscles of the blood 
of Hippopotamus amphihius, Otaria jubata , and Trichecus rosmarus. 
The Development of Marine Sponges is the subject of a couple of papers- 
appearing in the “ Annals of Natural History.” They are from the pen 
of Mr. LI. J. Carter, F.R.S., and give the results of his own observations,, 
which were conducted from the time when the ovum first appears to the 
condition of adult sponge. 
A Notice of a Taper on Embryology. — A capital notice is written in 
“Silliman’s American Journal” for Dec. 1874, on the subject of Kowa- 
levsky’s recent [Russian] papers on Embryology. In one of these the 
author, it is said [by Mr. Agassiz, jun., who is the writer], “continues 
the investigations he had been carrying on regarding the existence of an 
ectoderm and entoderm layer in the early embryonic stages of Invertebrates. 
In the present paper he has given a summary of the early stages of a Cam- 
panularia, confirming the observations of Wright and A. Agassiz. For 
Rhizostoma and Cassiopea he shows that the digestive cavity is formed by 
the invagination of the ectoderm. This is contrary to the results of previous 
observers, except Schneider. For Pelagia he shows a direct development 
from the egg remarkably similar to that of the Geryonidte as we know it 
from Hseckel, Fol, and Metschnikoff. He adds nothing to the embryology 
of Actinia not already known from the magnificent monograph of Lacaze- 
Duthiers. Lie then passes on to the development of Alcyonium, of which 
he gives an extremely interesting sketch, supplemented by fragments on the 
embryology of Astrsea, Gorgonia, and Ceriantkus ; the development of the 
latter is strikingly similar to that of Edw 7 ardsia, as we know it during its 
passage from Arachnactis to Edwardsia. He has added a few observations 
on the earlier embryonic stages of Eschscholtzia, Beroe, and Eucbaris, com- 
pleting deficiencies in his earlier papers on the embryology of Ctenophorae. 
These supplementary observations agree completely with the observations of 
A. Agassiz on the embryology of Ctenophorse.” 
Some Peculiarities of Amphioxus. — In a most important and valuable paper 
which Professor Huxley read before the Linnean Society, on Dec. 4, 1874, 
there are some passages on the subject of the curious little fish, the 
Amphioxus, which are of interest. The Professor says : — u Amphioxus, 
